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51.
Daniela Cocchi Angela Santagostino Irit Gil-Ad Sergio Ferri Eugenio E. Müller 《Life sciences》1977,20(12):2041-2046
The effect of Leu5-enkephalin on growth hormone (GH) and prolactin (PRL) release was studied in the infant rat and compared to that of morphine. In 10 day-old pups, intracerebroventricular injection of Leu5-enkephalin (50, 75 and 100 μg) resulted in a dose-related increase in plasma GH; morphine was active as GH releaser at the dose of 5 and 10 μg, but not at 2.5 μg. Pretreatment with naloxone (2 mg/kg ip) suppressed the GH-releasing effect of either Leu5-enkephalin (100 μg) or morphine (10 μg). Leu5-enkephalin (75 and 100 μg) induced a rise in plasma PRL which was neither dose-related nor antagonized by naloxone; morphine (5 and 10 μg) was active as PRL releaser and its effect was antagonized by naloxone. These results indicate that: 1) Leu5-enkephalin stimulates both GH and PRL release; 2) the release of GH by Leu5-enkephalin but likely not that of PRL involves specific opiate receptors; 3) morphine releases GH and PRL through specific opiate receptors. 相似文献
52.
53.
Natale Cascinelli Gian Paolo Balzarini Vincenzo Fontana Sergio Orefice Umberto Veronesi 《Cancer immunology, immunotherapy : CII》1977,2(3):157-161
Summary From November 1973 to December 1974, 20 patients with advanced malignant melanoma were treated with BCG given by intralymphatic route at the Cancer Institute of Milan. The lyophilized Pasteur BCG was used. Patients were treated with a single dose ranging from 0.2–80 mg. Patients' performance status was never severely impaired.The most frequent side effects were fever, lymphangitis, and lymph node enlargement.Variations were observed in white cell count, ERS and immunoglobulins; in no case did we find evidence of liver toxicity or tumor growth enhancement. It is concluded that the intralymphatic route is a safe way of administrating BCG. 相似文献
54.
Calmodulin copurifies with platelet plasma membranes isolated by glycerol-induced lysis and density gradient centrifugation. These membranes also bind 125I-labeled calmodulin in vitro in the presence of Ca2+. Binding is largely reduced by replacing Ca2+ by Mg2+ or by addition of an excess unlabeled calmodulin. The specific component of binding is saturable, with an apparent Kd of 27 nM and a maximum of 15.9 pmol binding sites per mg of membrane protein. This is equivalent to approx. 4100 binding sites per platelet. Binding was inhibited by addition of phenothiazines, a group of calmodulin antagonists. Half-maximal inhibition was attained with approx. 20 μM trifluoperazine or 50 μM chlorpromazine. In contrast, chlorpromazine-sulfoxide which is inactive towards calmodulin, did not affect the binding. Calmodulin binding polypeptides of the plasma membrane were identified by a gel-overlay technique. A major calmodulin-binding component of molecular weight 149 000 was detected. Binding to this band was Ca2+-dependent and inhibited by chlorpromazine. The molecular weight of this polypeptide is similar to that of glycoprotein I and also that of the red cell (Ca2+ + Mg2+)-stimulated ATPase, which is known to bind calmodulin. The possible role of calmodulin in platelet activation is analysed. 相似文献
55.
56.
Giacomo Carrea Alessandra Pilotti Sergio Riva Enrica Canzi Annamaria Ferrari 《Biotechnology letters》1992,14(12):1131-1134
Summary Dehydrocholic acid (3,7,12-trioxo-5-cholanic acid) (0.5% concentration) was completely and selectively reduced to 12-ketoursodeoxycholic acid (3, 7-dihydroxy-12-oxo- 5-cholanic acid) in a membrane reactor by means of 3-hydroxysteroid dehydrogenase and 7-hydroxysteroid dehydrogenase. Coenzyme regeneration was carried out with the glucose-glucose dehydrogenase system. 相似文献
57.
Raúl Alva J. Antonio Lugo-R Eduardo Arzt Jorge Cerbón Blanca E. Rivera Mireya Toro Sergio Estrada-O 《Journal of bioenergetics and biomembranes》1992,24(1):125-129
Nigericin is a monocarboxylic polyether molecule described as a mobile K+ ionophore unable to transport Li+ and Cs+ across natural or artificial membranes. This paper shows that the ion carrier molecule forms complexes of equivalent energy demands with Li+, Cs+, Na+, Rb+, and K+. This is in accordance with the similar values of the complex stability constants obtained from nigericin with the five alkali metal cations assayed. On the other hand, nigericinalkali metal cation binding isotherms show faster rates for Li+ and Cs+ than for Na+, K+, and Rb+, in conditions where the carboxylic proton does not dissociate. Furthermore, proton NMR spectra of nigericin-Li+ and nigericin-Cs+ complexes show wide broadenings, suggesting strong cation interaction with the ionophore; in contrast, the complexes with Na+, K+, and Rb+ show only clear-cut chemical shifts. These latter results support the view that nigericin forms highly stable complexes with Li+ and Cs+ and contribute to the explanation for the inability of this ionophore to transport the former cations in conditions where it catalyzes a fast transport of K+>Rb+>Na+.Part of the results of this paper were presented at the 14th International Congress of Biochemistry in Prague, Czechoslovakia. 相似文献
58.
Summary Androgenic plants have been obtained via anther culture in four natural populations of Hordeum spontaneum. Microscopic observations revealed that androgenesis started with the formation of two vegetative-type nuclei derived from the mitotic division of the uninucleate microspores. In this species androgenesis was affected by the type and concentration of the sugars added to the culture medium: the highest response (17% of callusing anthers) was observed on media containing 80 g l–1 maltose. The highest production of androgenic plants (per 100 anthers, 5.9 green and 4.3 albino plants) was obtained from callus grown on these same media. About half of the green plants regenerated were haploid, while the others were diploid and set seed.Abbreviations IAA
indolacetic acid
- BAP
6-benzylaminopurine 相似文献
59.
Shoot tips of M.4 apple clone were excised from actively growing one year-old stoolbed branches, and cultured in order to determine the optimal nutrient medium for each stage of their in vitro culture. The basal medium (BM) used was that described by Murashige and Skoog, supplemented with vitamins, glycine, myoinositol, sucrose, with or without agar, and different combinations of plant growth regulators. Best media for each stage were: BM+0.5 mg 1-1 indole-3yl-butyric acid (IBA)+0.5 mg 1-1 6-benzylaminopurine (BAP) for explant establishment (Stage I); BM+0.1 mg 1-1 IBA+1.0 mg 1-1 BAP for multiplication and internode enlargement (Stage II); and 2.0 mg 1-1 IBA+0.1 mg 1-1 BAP without agar for the rooting of the plantlets (Stage III). 相似文献
60.
Sergio Rodríguez 《Biosemiotics》2016,9(2):169-184
This article addresses the semiotic problem of how meaning is agentially grounded: how actual meaning is possible and is justifiably supported by agents’ capabilities and purposes. This article is particularly focused on human agential grounding; however, to a great degree, insights presented here can be extended to other living beings. Specifically, agential meaning is examined here inside the framework of agentive semiotics and embodied, situated and enactive cognition theories, in line with the mind-life continuity general thesis (which intends to naturalize mind and experience). To offer clarity and methodological precision about agential grounding, three explanation categories (called recurrences) are proposed: phylogenetic recurrence, the evolutionary basis for corporal/embodied grounding; ontogenetic recurrence, the developmental basis for individual meaning grounding; and collective recurrence, the basis for meaning recognized, attributed and assigned inside social contexts. These recurrences are conceived as three types of general processes that constantly enclose possibilities for purpose and meaning emergence in humans. As a result of these types of recurrences, two categories of human agendas or purposes are also proposed: individual and collective. Finally, remarks about how these categories can be useful for semiotic analysis and further research are suggested. 相似文献